Low temperature liquid metal batteries for energy storage applications

Abstract

The present invention relates to a molten metal battery of liquid bismuth and liquid tin electrodes and a eutectic electrolyte. The electrodes may be coaxial and coplanar. The eutectic electrolyte may be in contact with a surface of each electrode. The eutectic electrolyte may comprise ZnCl2:KCl.

Description

RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Patent Application 62 / 278,134, filed Jan. 13, 2016, which is hereby incorporated by reference it its entirety.GOVERNMENT SUPPORT[0002]This invention was made with Government support under grant PON2 1300001707 awarded by the Department for Energy Development and Independence. The Government has certain rights in the invention.TECHNICAL FIELD[0003]The present invention relates generally to a low temperature liquid metal battery operating at about 300° C. with a ZnCl2:KCl eutectic electrolyte and coaxial, coplanar liquid tin and bismuth electrodes.BACKGROUND[0004]It is imperative that sources of renewable energy be coupled with energy storage media for efficient and instant energy supplementation to the electrical grid. Large-scale stationary batteries offer several advantages over competing technologies (e.g. pumped hydro, compressed air storage, flywheels, and redox flow batteries) such as small environme...

AI Technical Summary

Benefits of technology

The system achieves stable and efficient energy storage with reversible cyclic performance over many days, maintaining capacity and power density, and allows for the investigation of high-temperature battery materials, addressing the limitations of existing technologies.

Problems solved by technology

Long cycle lifetimes will be required for stationary grid energy storage and membrane crossover (redox flow batteries) or electrode degradation (Li-ion and lead-acid batteries) lead to capacity loss over time despite intensive research.

Emerging LMB technologies have thus far been limited to materials (electrode and electrolyte) demonstrating this self-separating layered design which is attractive from a fabrication standpoint (i.e. at minimum, only a simple vessel with a metallic base contact is required) but the stratified design is susceptible to electrode dissolution or magnetohydrodynamic instabilities at high current densities which could lead to cell shorting and thermal runaway.

Furthermore, this specialized cell design (requiring immiscible materials with the density of molten salt between that of the anode and cathode) precludes many potential active and low-cost materials, and often requires exceedingly high operating temperatures (>500° C.).

Up to now, much research has foregone these marketable features, instead focusing on cells with reactive and costly components that achieve high power output or high nominal voltage.

ZEBRA, while capable of a moderate working temperature (245° C.) is limited in robustness with its beta alumina solid electrolyte and in safety with liquid Na and [AlCl4]− active components.

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